Heretofore, accurate analysis of the sulfur concentration in hydrocarbon samples has required separate measurement of the sample density. The sulfur analysis technique taught in U.S. Pat. No. 3,547,590 (Cropper et al., 1970), which is specifically incorporated herein by reference, is fully automatic but is nevertheless limited in the speed and convenience with which its readings can be used because they must be corrected by separate density measurement for accuracy desired increasingly. This limitation has been eliminated by the improved sulfur analysis technique claimed herein.